<template>
  <view class="uni-combox" :class="border ? '' : 'uni-combox__no-border'">
    <view v-if="label" class="uni-combox__label" :style="labelStyle">
      <text>{{ label }}</text>
    </view>
    <view class="uni-combox__input-box">
      <input class="uni-combox__input" type="text" :placeholder="placeholder"
             placeholder-class="uni-combox__input-plac" v-model="inputVal" @input="onInput" @focus="onFocus"
             @blur="onBlur"/>
      <uni-icons :type="showSelector? 'top' : 'bottom'" size="14" color="#999" @click="toggleSelector">
      </uni-icons>
    </view>
    <view class="uni-combox__selector" v-if="showSelector">
      <view class="uni-popper__arrow"></view>
      <scroll-view scroll-y="true" class="uni-combox__selector-scroll">
        <view class="uni-combox__selector-empty" v-if="filterCandidatesLength === 0">
          <text>{{ emptyTips }}</text>
        </view>
        <view class="uni-combox__selector-item" v-for="(item,index) in filterCandidates" :key="index"
              @click="onSelectorClick(index)">
          <text>{{ item }}</text>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
/**
 * Combox 组合输入框
 * @description 组合输入框一般用于既可以输入也可以选择的场景
 * @tutorial https://ext.dcloud.net.cn/plugin?id=1261
 * @property {String} label 左侧文字
 * @property {String} labelWidth 左侧内容宽度
 * @property {String} placeholder 输入框占位符
 * @property {Array} candidates 候选项列表
 * @property {String} emptyTips 筛选结果为空时显示的文字
 * @property {String} value 组合框的值
 */
export default {
  name: 'uniCombox',
  emits: ['input', 'update:modelValue'],
  props: {
    border: {
      type: Boolean,
      default: true
    },
    label: {
      type: String,
      default: ''
    },
    labelWidth: {
      type: String,
      default: 'auto'
    },
    placeholder: {
      type: String,
      default: ''
    },
    candidates: {
      type: Array,
      default() {
        return []
      }
    },
    emptyTips: {
      type: String,
      default: '无匹配项'
    },
    // #ifndef VUE3
    value: {
      type: [String, Number],
      default: ''
    },
    // #endif
    // #ifdef VUE3
    modelValue: {
      type: [String, Number],
      default: ''
    },
    // #endif
  },
  data() {
    return {
      showSelector: false,
      inputVal: ''
    }
  },
  computed: {
    labelStyle() {
      if (this.labelWidth === 'auto') {
        return ""
      }
      return `width: ${this.labelWidth}`
    },
    filterCandidates() {
      return this.candidates.filter((item) => {
        return item.toString().indexOf(this.inputVal) > -1
      })
    },
    filterCandidatesLength() {
      return this.filterCandidates.length
    }
  },
  watch: {
    // #ifndef VUE3
    value: {
      handler(newVal) {
        this.inputVal = newVal
      },
      immediate: true
    },
    // #endif
    // #ifdef VUE3
    modelValue: {
      handler(newVal) {
        this.inputVal = newVal
      },
      immediate: true
    },
    // #endif
  },
  methods: {
    toggleSelector() {
      this.showSelector = !this.showSelector
    },
    onFocus() {
      this.showSelector = true
    },
    onBlur() {
      setTimeout(() => {
        this.showSelector = false
      }, 153)
    },
    onSelectorClick(index) {
      this.inputVal = this.filterCandidates[index]
      this.showSelector = false
      this.$emit('input', this.inputVal)
      this.$emit('update:modelValue', this.inputVal)
    },
    onInput() {
      setTimeout(() => {
        this.$emit('input', this.inputVal)
        this.$emit('update:modelValue', this.inputVal)
      })
    }
  }
}
</script>

<style lang="scss" scoped>
.uni-combox {
  font-size: 14px;
  border: 1px solid #DCDFE6;
  border-radius: 4px;
  padding: 6px 10px;
  position: relative;
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  // height: 40px;
  flex-direction: row;
  align-items: center;
  // border-bottom: solid 1px #DDDDDD;
}

.uni-combox__label {
  font-size: 16px;
  line-height: 22px;
  padding-right: 10px;
  color: #999999;
}

.uni-combox__input-box {
  position: relative;
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  flex: 1;
  flex-direction: row;
  align-items: center;
}

.uni-combox__input {
  flex: 1;
  font-size: 14px;
  height: 22px;
  line-height: 22px;
}

.uni-combox__input-plac {
  font-size: 14px;
  color: #999;
}

.uni-combox__selector {
  /* #ifndef APP-NVUE */
  box-sizing: border-box;
  /* #endif */
  position: absolute;
  top: calc(100% + 12px);
  left: 0;
  width: 100%;
  background-color: #FFFFFF;
  border: 1px solid #EBEEF5;
  border-radius: 6px;
  box-shadow: 0 2px 12px 0 rgba(0, 0, 0, 0.1);
  z-index: 2;
  padding: 4px 0;
}

.uni-combox__selector-scroll {
  /* #ifndef APP-NVUE */
  max-height: 200px;
  box-sizing: border-box;
  /* #endif */
}

.uni-combox__selector-empty,
.uni-combox__selector-item {
  /* #ifndef APP-NVUE */
  display: flex;
  cursor: pointer;
  /* #endif */
  line-height: 36px;
  font-size: 14px;
  text-align: center;
  // border-bottom: solid 1px #DDDDDD;
  padding: 0px 10px;
}

.uni-combox__selector-item:hover {
  background-color: #f9f9f9;
}

.uni-combox__selector-empty:last-child,
.uni-combox__selector-item:last-child {
  /* #ifndef APP-NVUE */
  border-bottom: none;
  /* #endif */
}

// picker 弹出层通用的指示小三角
.uni-popper__arrow,
.uni-popper__arrow::after {
  position: absolute;
  display: block;
  width: 0;
  height: 0;
  border-color: transparent;
  border-style: solid;
  border-width: 6px;
}

.uni-popper__arrow {
  filter: drop-shadow(0 2px 12px rgba(0, 0, 0, 0.03));
  top: -6px;
  left: 10%;
  margin-right: 3px;
  border-top-width: 0;
  border-bottom-color: #EBEEF5;
}

.uni-popper__arrow::after {
  content: " ";
  top: 1px;
  margin-left: -6px;
  border-top-width: 0;
  border-bottom-color: #fff;
}

.uni-combox__no-border {
  border: none;
}
</style>
